framework学习笔记day09---Spring-Mybatis整合、web

事务的回滚和不回滚的异常

概述
- 默认情况，遇到运行时异常回滚，遇到编译期异常不回滚。
- rollbackFor设置需要回滚的异常
- noRollbackFor设置不需要回滚的异常

代码实现

//@Transactional(rollbackFor = FileNotFoundException.class,noRollbackFor = ArithmeticException.class)
@Transactional(rollbackFor = Exception.class)
@Override
public void addUser(User inputUser) throws Exception {
    System.out.println("UserServiceImpl addUser");
    userDao.addUser(inputUser);
    //运行时异常，会回滚
    System.out.println(1 / 0);
    //编译期异常
    //new FileInputStream("a");

}

事务的隔离级别

隔离级别
- 读未提交：可以读取到事务未提交的数据
- 读已提交：可以读取到事务中的数据前后不一致
- 可重复读：查询事务中的数据(id=1)不存在，添加该数据(id=1)已存在
- 串行化：效率低

代码实现

@Transactional(isolation = Isolation.REPEATABLE_READ)
@Override
public void addUser(User inputUser) throws Exception {
    System.out.println("UserServiceImpl addUser");
    userDao.addUser(inputUser);
    //运行时异常，会回滚
    System.out.println(1 / 0);
    //编译期异常
    //new FileInputStream("a");
}

@Transactional(isolation = Isolation.REPEATABLE_READ)
@Override
public List selectUserList() throws Exception {
    List userList = userDao.selectUserList();
    userList = userDao.selectUserList();
    return userList;
}

事务传播行为(难点)

概述
- 规定管理员中的事务和协调员中的事务的关系。
传播行为

事务传播行为演示(难点)

需求
- 进行转账业务时，进行日志记录。

REQUIRED

//事务管理员
@Transactional(isolation = Isolation.REPEATABLE_READ)
@Override
public List selectUserList() throws Exception {
    List userList = userDao.selectUserList();
    userList = userDao.selectUserList();
    return userList;
}

//事务协调员
@Transactional(propagation = Propagation.REQUIRED)
@Override
public void addLog(String content) throws Exception {
    logDao.addLog(content);
    System.out.println(1 / 0);
}

注意事项
- 传播行为应该在协调员进行设置.

Spring整合MyBatis概述

概述
- 将mybatis容器交给spring容器管理
传统dao开发
- dao接口 + dao实现子类 + mapper映射文件 + spring容器
- 本质是将dao实现子类交给spring容器管理
接口代理开发
- dao接口 + mapper映射文件 + spring容器
- 本质是将dao接口代理对象交给spring容器管理

Spring整合MyBatis之传统dao开发

概述
- 本质将dao实现子类交给Spring容器管理
开发步骤
- ①引入相关依赖
- ②定义service及其实现子类
- ③定义dao及其实现子类
- ④编写spring-core.xml
  - 扫描注解
  - 将SqlSessionFactory对象交给Spring容器管理(使用SqlSessionFactoryBean)，FactoryBean机制
    - 加载mybatis核心配置文件SqlMapConfig.xml
  - 将DruidDataSource对象交给Spring容器管理
- ⑤代码测试

①引入相关依赖


    8
    8
    4.13.2
    1.18.22
    5.3.13
    1.7
    1.2.8
    5.1.48
    3.5.7
    2.0.6




    
    
        junit
        junit
        ${junit.version}
        test
    
    

    
    
        org.projectlombok
        lombok
        ${lombok.version}
    
    

    
    
        org.springframework
        spring-core
        ${spring.version}
    
    
        org.springframework
        spring-beans
        ${spring.version}
    
    
        org.springframework
        spring-context
        ${spring.version}
    
    
        org.springframework
        spring-expression
        ${spring.version}
    

    
        org.springframework
        spring-test
        ${spring.version}
    

    
        org.springframework
        spring-jcl
        ${spring.version}
    

    
        org.springframework
        spring-aop
        ${spring.version}
    

    
        org.springframework
        spring-aspects
        ${spring.version}
    

    
        org.springframework
        spring-jdbc
        ${spring.version}
    

    
        org.springframework
        spring-tx
        ${spring.version}
    
    


    
    
        org.mybatis
        mybatis-spring
        ${mybatis-spring.version}
    
    


    
    
        org.mybatis
        mybatis
        ${mybatis.version}
    
    

    
    
        com.alibaba
        druid
        ${druid.version}
    
    
        mysql
        mysql-connector-java
        ${mysql.version}

②定义service及其实现子类

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserDao userDao;

    @Override
    public List selectUserList() throws Exception {
        return userDao.selectUserList();
    }
}

③定义dao及其实现子类

@Repository
public class UserDaoImpl implements UserDao {

    @Autowired
    private SqlSessionFactory sqlSessionFactory;
    @Override
    public List selectUserList() throws Exception {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        List userList = sqlSession.selectList("selectUserList");
        sqlSession.close();
        return userList;
    }

}

④编写spring-core.xml

⑤代码测试

public class UserController {

    public static void main(String[] args) throws Exception {
        //Spring容器初始化
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring-core.xml");

        UserService userService = applicationContext.getBean(UserService.class);
        List userList = userService.selectUserList();
        System.out.println("userList = " + userList);
    }

}

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:spring-core.xml")
public class UserServiceTest {

    @Autowired
    private UserService userService;
    @Test
    public void selectUserList() throws Exception {
        List userList = userService.selectUserList();
        System.out.println("userList = " + userList);
    }
}

存在问题
- 每次都需要通过SqlSessionFactory获取SqlSession对象并使用，结束后还得关闭，比较麻烦。

Spring整合MyBatis之传统dao开发优化

概述
- 使用SqlSessionDaoSupport类

优化一

@Repository
public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao {


    //给UserDaoImpl的父类SqlSessionDaoSupport注入SqlSessionFactory对象
    @Autowired
    @Override
    public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
        super.setSqlSessionFactory(sqlSessionFactory);
    }

    @Override
    public List selectUserList() throws Exception {
        List userList = getSqlSession().selectList("selectUserList");
        return userList;
    }

}

优化二

public class baseDao extends SqlSessionDaoSupport {

    @Autowired
    @Override
    public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
        super.setSqlSessionFactory(sqlSessionFactory);
    }
}

@Repository
public class UserDaoImpl extends baseDao implements UserDao {


    @Override
    public List selectUserList() throws Exception {
        List userList = getSqlSession().selectList("selectUserList");
        return userList;
    }

}

Spring整合MyBatis之接口代理

概述
- 本质将接口代理对象交给Spring容器管理
开发步骤
- ①定义service接口及其实现子类
- ②定义dao接口
- ③编写spring-core.xml
  - 扫描注解
  - 将dao接口代理类对象放入Spring容器(使用MapperFactoryBean)
  - 将SqlSessionFactory对象放入Spring容器(使用SqlSessionFactoryBean)
  - 将DruidDataSource对象放入到Spring容器
- ④代码测试
①定义service接口及其实现子类
②定义dao接口

③编写spring-core.xml

④代码测试
存在问题
- ①在SqlMapConfig.xml文件中，不需要再通过标签加载映射文件
- ②如果有100个mapper接口，那么就需要写100次将mapper接口代理类对象放入到Spring容器，过于麻烦。

Spring整合MyBatis之接口代理优化

概述
- 使用MapperScannerConfigurer

代码实现

Spring整合MyBatis引入logback

开发步骤
- ①引入相关依赖
- ②编写logback.xml
- ③代码测试

①引入相关依赖


    ch.qos.logback
    logback-classic
    1.2.7


    org.slf4j
    slf4j-api
    1.7.32

②编写logback.xml



    
    
        
            
            
            [%d{HH:mm:ss.SSS}] [%-5level] [%thread] [%logger] [%msg]%n

③代码测试

public class UserController {

    public static Logger logger = LoggerFactory.getLogger(UserController.class);

    public static void main(String[] args) throws Exception {
        //Spring容器初始化
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring-core.xml");

        UserService userService = applicationContext.getBean(UserService.class);
        List userList = userService.selectUserList();
        logger.debug("userList : " + userList);
    }

}

Spring整合MyBatis引入分页插件

开发步骤
- ①引入相关依赖
- ②编写UserService
- ③编写SqlMapConfig.xml
  - 配置PageInterceptor
- ④代码测试

①引入相关依赖


    com.github.pagehelper
    pagehelper
    5.2.1

②编写UserService

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;


    @Override
    public PageInfo selectUserListByPage(Integer currentPage, Integer pageSize) throws Exception {
        PageHelper.startPage(currentPage,pageSize);
        List userList = userMapper.selectUserList();
        return new PageInfo<>(userList);
    }
}

③编写SqlMapConfig.xml
```
    
        
    
```

Spring整合MyBatis引入事务管理

开发步骤
- ①编写spring-core.xml
  - 开启支持事务注解
- ②编写UserService
  - 使用@Transactional注解
①编写spring-core.xml
```
    
```

②编写UserService

@Transactional
@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    @Override
    public void addUser(User inputUser) throws Exception {
        userMapper.addUser(inputUser);
        System.out.println(1 / 0);
    }

    @Override
    public List selectUserList() throws Exception {
        return userMapper.selectUserList();
    }

    @Override
    public PageInfo selectUserListByPage(Integer currentPage, Integer pageSize) throws Exception {
        PageHelper.startPage(currentPage, pageSize);
        List userList = userMapper.selectUserList();
        return new PageInfo<>(userList);
    }
}

Spring整合web环境第一版

需求
- 在JavaWeb程序中使用Spring容器（在UserServlet中使用Spring容器中的UserService对象）
开发步骤
- ①创建web项目
- ②Spring整合MyBatis
- ③编写UserController
①创建web项目
②Spring整合MyBatis

③编写UserController

@WebServlet("/selectUserList")
public class UserController extends HttpServlet {


    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //初始化Spring容器
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring-core.xml");
        UserService userService = applicationContext.getBean(UserService.class);
        try {
            //使用Spring容器中的UserService对象
            List userList = userService.selectUserList();
            System.out.println("userList = " + userList);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

存在问题
- 发起一次请求UserController，就会创建一次Spring容器。

Spring整合web环境第二版

概述
- Spring容器只需要初始化一次，在后续的操作中都能够一直被使用。
解决方案
- 服务器启动，项目启动，就初始化Spring容器，使用ServletContextListener监听器；

代码实现

public class MyContextLoaderListener implements ServletContextListener {

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        //项目启动，初始化Spring容器
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring-core.xml");
        sce.getServletContext().setAttribute("applicationContext", applicationContext);
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        //项目销毁
    }
}


    com.atguigu.listenter.MyContextLoaderListener

@WebServlet("/selectUserList")
public class UserController extends HttpServlet {


    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //初始化Spring容器
        //ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring-core.xml");
        ApplicationContext applicationContext = (ApplicationContext) getServletContext().getAttribute("applicationContext");
        UserService userService = applicationContext.getBean(UserService.class);
        try {
            //使用Spring容器中的UserService对象
            List userList = userService.selectUserList();
            System.out.println("userList = " + userList);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

存在问题
- 存在"spring-core.xml"、"applicationContext"字符串硬编码问题。

Spring整合Web环境第三版

概述
- 将"spring-core.xml"设置web.xml中；
- 将"applicationContext"放入到工具类中

代码实现


    Archetype Created Web Application

    
    
        contextConfigLocation
        classpath:spring-core.xml
    

    
        com.atguigu.listenter.MyContextLoaderListener

public class MyContextLoaderListener implements ServletContextListener {

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        //获取contextConfigLocation全局变量的值=spring-core.xml
        String contextConfigLocation = sce.getServletContext().getInitParameter("contextConfigLocation");
        //项目启动，初始化Spring容器
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext(contextConfigLocation);
        sce.getServletContext().setAttribute("applicationContext", applicationContext);
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        //项目销毁
    }
}

public class MyApplicationContextUtils {


    public static ApplicationContext getApplicationContext(ServletContext servletContext){
        return (ApplicationContext) servletContext.getAttribute("applicationContext");
    }

}

@WebServlet("/selectUserList")
public class UserController extends HttpServlet {


    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //初始化Spring容器
        //ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring-core.xml");
        ApplicationContext applicationContext = MyApplicationContextUtils.getApplicationContext(getServletContext());
        UserService userService = applicationContext.getBean(UserService.class);
        try {
            //使用Spring容器中的UserService对象
            List userList = userService.selectUserList();
            System.out.println("userList = " + userList);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

存在问题
- 特别麻烦，不要自己写，Spring已经提供给你了！！

Spring整合Web环境终极版

概述
- Spring框架提供了ContextLoaderListener、WebApplicationContextUtils
开发步骤
- ①引入相关依赖
- ②编写web.xml
  - 配置ContextLoaderListener
- ③编写UserController
  - 使用WebApplicationContextUtils

①引入相关依赖


    org.springframework
    spring-web
    ${spring.version}



    org.springframework
    spring-webmvc
    ${spring.version}

②编写web.xml


    contextConfigLocation
    classpath:spring-core.xml



    org.springframework.web.context.ContextLoaderListener

③编写UserController

@WebServlet("/selectUserList")
public class UserController extends HttpServlet {


    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        ApplicationContext applicationContext = WebApplicationContextUtils.getWebApplicationContext(getServletContext());
        UserService userService = applicationContext.getBean(UserService.class);
        try {
            //使用Spring容器中的UserService对象
            List userList = userService.selectUserList();
            System.out.println("userList = " + userList);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

注意事项
t.ContextLoaderListener

③编写UserController

@WebServlet("/selectUserList")
public class UserController extends HttpServlet {


    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        ApplicationContext applicationContext = WebApplicationContextUtils.getWebApplicationContext(getServletContext());
        UserService userService = applicationContext.getBean(UserService.class);
        try {
            //使用Spring容器中的UserService对象
            List userList = userService.selectUserList();
            System.out.println("userList = " + userList);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

注意事项
- 在web项目中，引用第三方配置文件时，需要在前面加上"classpath"，比如:classpath:SqlMapConfig.xml"、“classpath:jdbc.properties”

framework学习笔记day09---Spring-Mybatis整合、web

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